ACER answers the question: What are Ecosystem Services?


A low relief oyster reef adjacent to the marsh on Little Dauphin Island, AL. Photo credit: D.Byron

In this installment of Word Wednesday by the Alabama Center for Ecological Resilience (ACER), we answer the question: What are ecosystem services?

As humans, we sometimes underestimate the importance of intact and healthy ecosystems. Simply by their physical presence and normal day-to-day functioning, healthy, intact ecosystems benefit humans. These benefits are known as ecosystem services.

For example, oyster reefs create habitat for organisms other than oysters. Many commercially and recreationally important animals such as blue crab, shrimp and many types of fishes are more common around oyster reefs than in surrounding waters. The benefits from intact healthy ecosystems can be small or large, direct or indirect, but a key element is that humans do not pay for them.

Ecosystem services have been categorized into 4 major groups: provisioning services such as providing food or raw materials for people; regulating services such as pollinating crops and trees; habitat or supporting services such as providing habitat for other organisms or maintaining genetic diversity; and cultural services such as recreation or aesthetic pleasure.

Some of these ecosystem services are more obvious to humans and financial benefits more easily valued than others. For example, ecotourism has grown out of the recognition that humans will pay to see rare and endangered species, watch birds, hike unspoiled areas, or raft down undammed rivers. Less obviously, the recent die off of honeybees has resulted in farmers having to rent bees during critical pollination times so that crop yields are maintained. It is estimated that the value of pollination services in the US alone is $4,000,000,000-6,000,000,000 (billion) per year. But how do we put a dollar value on the role that soils play in absorbing water and improving water quality or that plant root systems play in anchoring land and preventing soil erosion?


Marsh plants help anchor soil, providing an important ecosystem service, photo credit: J. Moody

Without this dollar value, ecosystem services are not explicitly considered in cost – benefit analyses, an important component of many development, construction and restoration projects. Recognizing this, ecologists and economists have been collaborating to develop science-based dollar figures for ecosystem services that are more difficult to value. For example, the city of Breaux Bridge, Louisiana chose to use a local wetland to have nature carry out final (tertiary) treatment of their sewage runoff before discharge to local waters. The reported cost savings of this ecosystem services based approach, rather than a conventional approach (adding an additional treatment phase to their waste processing facility), was $2.6 million over a 20-year period.

Through their research, ACER scientists are contributing to the science underlying the valuation of ecosystem services provided by several types of coastal habitats in the Gulf. By identifying and measuring the suite of services performed by salt marshes, oyster reefs, seagrass beds and other nearshore habitats, it will be possible for resource managers to financially quantify their loss and evaluate plans for their restoration.